The present invention relates, in general, to a residual-current circuit breaker and to a method for detecting direct residual currents and alternating residual currents in a residual-current circuit breaker.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
Residual-current circuit breakers are known which are arranged for detecting alternating residual currents and for detecting direct residual currents. Such residual-current circuit breakers comprise two completely separated residual-current detection devices which have a separate summation current transformer. Summation current transformers represent both one of the most expensive and bulky modules within a residual-current circuit breaker. Moreover, one needs to be exceptionally careful in processing the same because mechanical stresses on the core of a summation current transformer can have a negative effect on its functionality.
It would therefore be desirable and advantageous to provide an improved residual-current circuit breaker which obviates prior art shortcomings and which can be produced in a simple and cost-effective manner and which requires little space and is yet reliable in operation.